In my U.S. Pat. No. 4,903,961 of Feb. 27, 1990 there is disclosed a rowing machine of the type in which a pair of generally oblong water-filled tanks straddle a third tank in which an oarsman sits and manipulates either a single or a pair of oars in one or both side tanks. Each of the side tanks is provided with fluid diverting means to enhance the water flow therein. The diverting means includes a central vertical wall separating the tank into the parallel sections and a plurality of horizontally oriented flow plates supported at each end of the tank connecting the two sections. When rowing, the rower pushes water in one section which then circulates within the tank being assisted in such movement by the diverting means. Such construction exhibited improved water action and wave motion over the then known apparatus of this type although only limited flow of water is obtained.
While the apparatus is highly effective as a training device and provides sufficient water flow to simulate a sense of movement, water resistance is, however, significantly larger than would be normally encountered by the rower in a river or lake. This resistance is largely the rower must push a relatively large body of stationary water and keep the water in motion. Moreover, an added problem exists because the diverting means used at each end of the tank and the solid center wall tends to produce water cavitation, as well as whirlpool and eddy effects, as the speed and rapidity of the rower's action increased.
In order to alleviate the foregoing disadvantages, an improved rowing apparatus was developed which is disclosed and claimed in my U.S. Pat. No. 5,306,219 issued Apr. 26, 1994. In this apparatus the oblong tanks are provided with a dividing wall assembly having a plurality of transverse passages acting to short circuit at least a portion of the water from one parallel section of the tank to another. In addition, the flow diverter is located at each end of the tank having a plurality of horizontally disposed, vertically spaced plates supported by a plurality of vertically oriented walls spaced parallel to each other between adjacently stacked pairs of plates which define a plurality of arcuate passages between the parallel section. While such construction provides improved water flow and reduced cavitation, it still does not provide for increased simulated speed, or natural water flow, again largely because a single rower pushes all the water in the tank. Moreover, neither of the previous apparatuses can be used to accommodate a plurality of rowers.
There exists, therefore, a need to provide a simplified construction which can be used by a plurality of rowers and which at the same time exhibits improved water flow and which permits simulating increased speeds in the water. The present invention fulfills such a need. Other objects and advantages are stated in the foregoing disclosure of the present invention.